On 12/15/05, kashani <[EMAIL PROTECTED]> wrote: > Assuming this is a small home system I'd go with RAID 5 with maybe a > hot spare if I have more than four drives in a normal server setting > where reads happen more often than writes. That's more space with > comparable performance for anything you're likely to be doing.
I would say the choice between RAID 5 and RAID 0+1 would be based upon what you are doing. Assuming a 4-disk array, RAID5 will require 2 reads and 2 writes for writing a single block of data, while the RAID0+1 array would only require 2 writes. Read performance with RAID5 should be at least 75% of the RAID0+1 setup, possibly equal depending upon the bandwidth of the PCIe bus. So if you are doing something like video streaming, RAID0+1 would be a better choice. Web browsing, email, compiling, and typical desktop use would be well suited to RAID5. Also, consider that you can mix-and-match RAID levels with different partitions. You can create a 4-partition RAID0 array for swap, a 4-partition RAID0+1 array for filesystems that experience a lot of writes (/var, /tmp, and maybe /usr/src, for example), and a 4-partition RAID5 setup for /root, /home, et al. If a disk fails, your system would likely crash (due to the swap device), but would reboot in a degraded mode (no swap, slow performance, etc). I wouldn't overdo the complexity here, but the above becomes quite a bit easier to manage if you combine RAID with LVM or EVMS to manage your filesystems. -Richard -- gentoo-user@gentoo.org mailing list
